Thirty-day rehospitalizations are costly for both patients and hospitals, and programs to better support vulnerable patients may help prevent some rehospitalizations. In this retrospective cohort study, the authors evaluated the association between neighborhood socioeconomic disadvantage and 30-day rehospitalization. They concluded that living in a disadvantaged neighborhood is a predictor of rehospitalization and that measures of neighborhood disadvantage could be used to inform policy and care after discharge.

A national debate on whether social risk factors should be included in models developed for hospital profiling is ongoing. The authors compared a Centers for Medicare&Medicaid Services–based model of 30-day stroke readmission with a more comprehensive model that includes measures of social risk (such as homelessness) or clinical factors (such as stroke severity and functional status). More comprehensive models did not affect hospital comparisons based on 30-day readmission rates.

Type 2 diabetes is associated with dementia risk, but whether diabetes and prediabetes are associated with cognitive decline is unclear. In this prospective cohort study, the authors sought to determine whether diabetes in midlife is associated with 20-year cognitive decline and to characterize long-term cognitive decline across clinical categories of hemoglobin A1c levels. Their results suggest that diabetes prevention and glucose control in midlife may protect against cognitive decline later in life.

Geographic variations in the use of medical care have led policymakers to question whether care in high-volume areas can be reduced without lowering quality. The authors compared average use and geographic variation in cancer-related imaging between patients in the Veterans Affairs (VA) health care system and Medicare patients. Care was less expensive for VA than Medicare patients, and the cost of care in different areas varied as much for VA patients as for Medicare patients.

Reviews

The use of health information exchange (HIE) is increasing in the United States. This systematic review evaluated the use of HIE and its effect on clinical care. Authors found that HIE use can reduce emergency department use and costs, but the effect of HIE on other outcomes is unknown. A small number of HIE organizations were evaluated for their effects on outcomes of care, and further study is needed.

Evidence needed in the development of clinical practice guidelines to evaluate the tradeoffs between benefits and harms is often not provided by systematic reviews of primary research. In this article, the authors identify gaps between published evidence and the information needed for guideline development and consider modeling studies as an approach to bridge these gaps.

This updated U.S. Preventive Services Task Force recommen-dation on aspirin prophylaxis in pregnancy applies to asymptomatic pregnant women who are at increased risk for preeclampsia and who have no prior adverse effects with or contraindications to low-dose aspirin. The Task Force recommends the use of low-dose aspirin (81 mg/d) as preventive medication after 12 weeks of gestation in women who are at high risk for preeclampsia.

Ideas and Opinions

Chikungunya fever, a debilitating but rarely fatal disease, is increasing in frequency among travelers returning to the United States from affected regions. The mosquito vectors for this virus are widespread within U.S. borders. Clinicians thus must be aware of the presentation, diagnosis, and management of this infection.

Editorials

In this issue, Kind and Keyhani and their colleagues evaluated the effects of neighborhood and individual socioeconomic status and clinical factors on 30-day rehospitalization rates and hospital performance. The editorialists discuss these studies and stress that quality assessment should reflect how well hospitals care for their patients regardless of financial circumstances.

In this issue, McWilliams and colleagues report on geographic variation in cancer-related imaging between the VA health care system and Medicare. The editorialists discuss this research and argue that it provides reasonable evidence to contradict the assumption that high variation in care reflects overuse.